1. Field of the Invention
Apparatuses consistent with the present invention relate to an ultra wideband antenna, and more particularly to an ultra wideband antenna that intercepts transmission/reception of a predetermined frequency band signal using a radiator with a stub having a length of λ/4 inserted thereto.
2. Description of the Related Art
All antennas are used to convert an electric signal into a specified electromagnetic wave to radiate the converted electromagnetic wave to free space, or to convert a received electromagnetic wave into an electric signal. Ultra wideband (UWB) technology refers to a wireless transmission technology that directly transmits and receives an impulse signal without using an RF carrier. An ultra wideband antenna is an antenna that can transmit and receive an impulse signal using a frequency band in the range of 3.1 to 10.6 GHz.
Ultra wideband technology can achieve a high-speed data transmission using an ultra low power due to the use of a very wide frequency band, unlike the existing narrow-band communication method. Accordingly, ultra wideband can be applied to a home networking application such as a wireless personal area network (WPAN), which has become increasingly popular.
FIG. 1 is a block diagram illustrating the construction of a conventional receiving system using an ultra wideband antenna. Referring to FIG. 1, the conventional receiving system includes an ultra wideband antenna 10, a filter unit 20, a matching unit 30 and an amplifying unit 40.
The ultra wideband antenna 10 receives signals in the frequency range of 3.1˜10.6 GHz.
The filter unit 20 removes signals in the frequency range of 5.15˜5.825 GHz among the signals received from the ultra wideband antenna 10. The frequency band of 5.15˜5.825 GHz has also been used in the wireless LAN (WLAN) communication service standard (e.g., HIPERLAN/2, IEEE 802.11a).
As a result, the frequency band of 5.15˜5.825 GHz may cause interference with WLAN signals, and thus the system removes signals in this frequency band using the filter unit 20. For this, the filter unit 20 may be implemented by a notch filter that passes only the remaining signals except for a predetermined frequency band.
The matching unit 30 matches the impedance of the antenna to the impedance of a power feeding cable (not illustrated). The amplifying unit 40 amplifies the received signal and outputs the amplified signal to the following circuit. Detailed explanation of other constituent elements of the receiving system will be omitted.
In the conventional receiving system as described above, the ultra wideband antenna 10 and the filter unit 20 have been implemented as separate circuits, and this causes the entire size of the receiving system to be increased. Also, since many constituent elements exist in the receiving system, the power loss is great and the system construction is complicated. Accordingly, research of an ultra wideband antenna having a filter function capable of removing signals in a predetermined frequency band has been proposed.